Tuning mechanism



April 25, 1950 s. A. HALLv TUNING MECHANISM4 Filed March 20, 1946 .1. ,Q "mmm wm [N V EN TOR.

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Patented Apr. 25, 1950 l TUNING MECHANISM Stanley A. Hall, Vancouver, British Columbia, Canada Application March 20, 1946, Serial No. 655,693

My invention relates in general to tuning mechanisms and in particular to those mecha.- nisms in which a flux conducting member is moved relative to an inductance element by partially coiling and uncoiling band means n a rotatable drum.

An object of my invention is the provision of a device for reciprocally moving a first member with respect to a second member without establishing a backlash in the device.

Another object of my invention is the provision of a device for reciprocally moving a first member with respect to a second member in which a drum is rotated to coil bands thereon for moving said first member.

Still another object of my invention is the provision of a tuning device having a movable element in which a drum having bands cooperating therewith is rotated to move the movable element for tuning the device.

A further object of my invention is the provision of a variable reactor having a flux conducting member movable relative to the inductance elements to vary the reactance of the reactor.

A still further object of my invention is the provision of a manually rotatable drum means and cooperative band means which may be partially coiled onto and uncoiled from the drum means to reciprocally move a flux conducting member relative to an inductance element for varying the reactance of the inductance element.

I have for a still further objectof my invention, the provision of a variable reactance in which a first band means extends partially about a rotatable drum in one direction and a second band means extends partially about the drum in the opposite direction to cooperate with the drum to move a flux conducting member rela- ;tive to an inductance element when the drum is vmy tuning mechanism; and

Figure 4 of my drawingsv is a cross-sectional yiew taken along the line 4-4 of Figure 3.

2 claims. (o1. 74--1o.7

Aany desired circuit connection without departing from the scope of my invention.

" In the preferred embodiment of my invention", the reactance IU is supported by a base II. The reactance Ill is Varied by moving a flux conducting member I2 and a ux conducting member I9 relative to the coils of wire 22 and 24. These flux conducting members i2 and I9 may be reciprocally moved by reciprocally sliding a movable member I3 on the bed I4 of the base II. In my preferred tuning mechanism, this movable member I3 is reciprocated on the bed I4 by a rotatable drum I5 and ilexible bands I6, I'I and I8. The flexible bands I6, Il and IS and the rotatable drum I5 cooperate when the drum is rotated in one direction to move the movable member I3 along the bed I4 in a desired direction. The flexible bands IS, I'l and I8 and the rotatable drum I5 cooperate to move the movable member in the opposite direction on the bed I4 When the drum is rotated in the opposite di rection.

The reactance I!) comprises in general the first;

coil of wire 22 coiled on an insulation tube 23,4 and the second coil of wire 24 coiled on a second insulation tube 25. The first insulation tube 23, which is supported above the base II by an upright member 2S and collar 2l, has its axis substantially parallel to the plane of the bed I4. The collar 21 extends about one endv of the insulation tube 23 and may be welded or otherwise fastened to the upright member 26. Similarly, the insulation tube 25 having the coil wire 2t thereon, is supported by the upright member 26 and a collar 28. The longitudinal axes of those insulated tubes 23 and 25, while being substantially in a plane parallel to the bed I4 of the base Il, are also substantially parallel each with the other. Y

Adjustable condensers 30 and 2l may be supported Within the base II by a supporting plate 32. This supporting plate 32 may be constructed of any suitable insulation material and may be fastened by screws 33 to tabs 34, which may be constructed by punching inwardly a portion of the wall of the base II. The wire coils 22 and 24 and the adjustable condensers 30 and 3l may be connected in suitable electrical circuit onto the electrical contacts 35. These contacts 35 are supported by the supporting plate 32 and extend outwardly through the base II for external electrical connection. It is to be understood, that .these adjustable condensers and the coils of wire which form the reactance may be connected in The flux conducting members I2 and I9 are `reciproca-Hy slidably mounted within the insulation tubes 23 and 25, respectively. In my specification and claims, I will describe only one of these units, as the other unit is similarly constructed. The flux conducting members may be constructed of any suitable material, such for example, as ferrous metals. A threaded portion 31 of the ux conducting member I9 l"extends longitudinally therefrom on one end. This threaded portion 3l extends through an opening in a bracket 39 and may be secured thereto by nuts 38. The bracket 39 may be constructed -of any suitable material and .has generally an L-shape with the base of the bracket 39 fastened by a rivet 40 or other suitable means to one end 2n of the movable member I3.

A first end of each of the side bands lII :and I=8 is fastened by riveting or other suitable means to the end 20 of the movable member I3 and A.on opposite sides thereof. These side bands IB .and I8 are coiled 4partially .about the rotatable drum I5 inone direction. A second -end of these side bands f6 and AIi'is fastened by welding,.soldering, or .other Afastening means to vthe .rotatable drum Il5. The 'bands .are preferably constructed of .a flexible material, such .for example, .brass .or

copper, which Wlillreadily coilabout therotatable drum yas the drum is manually rotated. As is best illustrated in the VFigure 3. of .my drawing, the flexible side bands lland 1I9 areiastened on opposite side ends of the .rotatable drum-I5 and are .disposed to. engage the substantially cylindrical surface '45 .of the drum. One end .of the center band 'I'I is fastened to the manually .rotatable .drum lin a manner similar to the .side bands I6 and IIB, but .ispartiallyicoiled .about @the diz-um v.in the .opposite direction. 'The Iother .end of Athe centerband I'I vis fastene'dby a spring 4I to the center of the opposite end 2| `of .themovablemember I3. This center band yI 1 .is (disposed to coil. substantially intermediate the ends .of .the rotatable drum I5. 'The yspring III', .although shown. as a bent wire riveted to the movable member I3, may be of any other..suitable..des`ign without departing from the scope of .my invention, and .prevents any .s'lackness orllo'oseness between the bands-and. .the rotatable drum.

The rotatable .drum .5.5 .may .be suitably .mounted within the .basel I by izfollerbearing-means H2 or otliersuitable. means, vwherebyit.may bemanually rotated by aknob '43. Tlaislcnob. 333. may

.e .carried by.. a shait. lili v.which extends'. outwardly from.` the .rotatable drum .f5 .andllthrough the base. IAI best.'shown inl-.Tigure f4' of. my drawing, -the cylindrical surface "45 of' the drum 'l5 is disposed.from..the .movable member i3 a. distance slightly greater 'th'anthe 'thickness of the bandsljflandrl.

The major axes of the'ba'nds I5, 'Il' and I9 are substantially. 'perpendicular to the longitudinal 'aXi'snf the rotatabledrum I5; Tliese'ba'n'ds andfth'e' -drinn 'are t`hus"aiigned *te permit the bandstotbe'cdiled'cnto the drum'without`travei-- ing longitudinally thereof. The combination of- 'thevtwosid'e bands I 'Si and Hi and-thev` cerlter- Vband t? coiling'on-tothe drum-in=opposite directions causes fthe L'movable member IE' to freeipro'cally sl-ide lo'n the bed if@ `=in sulbstantiallyfa -straiht line.

f'In operation, as the knob de isturned "byT-the .operat'orin lione direct-ion, stl'freside #bands Ibi-and '1 Ifa will-be :coiled tontoLitheirctatableadrum b5, and

simultaneously thescenter Iband fllliwill. .tbe-nin 4 coiled from the rotatable drum I5. The cooperation of these bands I6, II and I8 with the rotatable drum will cause the movable member I3 to be moved in a first direction and thereby move the flux conducting members I2 and I9 Within the insulation tube and in the first direction to vary the reactance. The bands I6 and I8, when coiled onto the manually rotatable drum I5, move the movable member 123, Vwhicl'i iin turn operates to `uncoil the center 'fband I' from the drum. When the drum is rotated in the opposite direction, the bands I5 and I8 will be uncioileii .trom the drum and the center band Il coiled onto the drum to move the movable memb'er in the opposite direction and thereby move the flux conducting members partially within the li'nsulation vtubes .2'3 .fand 25. When the drum is rotated in this opposite direction, the center band "II is coiled onto .the drum and moves the movable member I3, which in turn uncoils the side bands Ii and I 8 from the drum.

vvThe 'comblnation'df r'the *two side ibands 'I-' `and :Hl and the centerband ITI coiling -onto thefdrum in opposite directions Icauses the :movable mem- -oer fi 3 Ito `reoiprccail-Ly -slide ron the berl fi l in `substantially a straight line. The movablemember l-, 'thus always lbeing aligned 'with the bed i4 and 'ith-us with the 'ire'adtance I0, 4keeps vthe `flux conducting members |72 Aand Il-9 ysubstantially :in alignment withtheir :respective Ainsulation atubes and :coils .of '.Wire.

'The ceiling and :unc'oiling .of these bands alli., dll' and 5.8,:asipreviouslyescribed onto the drum 11o izeciprecate `the 'movable member I .3, :also veliminates what is commonly .known as backlash The drum may lberctated .to move the movable mem-ber .in 'one adir-cation .and then rotated op- @ositel-y tto :move the :movable member in -the op- .posite direction rwithout permitting :any Aplay or laxness between the movement =1of :the -dium and `the'movement tof lthemevable 4:member '.IS. .Thus, .a :smooth .reciprocal .operation -.or vmovement of the movable member., .and thereby smooth variation ro1" the -reactance I 0, may -be vhad by .the .re-

iill) Although I hayeldescrlbed my invention in its v@preferred .form with .a -certain degree .of `particu- .lai.fity..it.is runderstood .that .the presentdisclosure `of dheV ,preferred .form .has been .rmade only .by vvay of .example `and that numerous `changes in the .details .of Aconstruction .and .the combination .and .arrangement of L.parts may be resorted to Without departing .from the spiritand the .scene of the invention as lherein'after claimed.

`What is claimed fis:

`1. .A .unit for .moving `a .tuning .rod .relative .to an 'inductance .coi1,.said un'iticomprising, .a .frame fhaying. opposite Lside walls .defining .a pair of .spaced parallel .runner surfaces, .turnable .drum means bearing in .saidside .walls .and -extending .therebetween transversely .of said .runner surfaces, a s'led reciprocally slidable on said runner surfaces, said sled having a `first and .a-second end, a tuning rod support means-.fastened'to one 'o'f said ends' of said sled and extending outwardly therefrom, first band means windably mounted inone direction on said drum means and extending therefrom Ytowards said first end -of'saidsled,se'ccnd band means `windably'moimted on saids'drummeans'in an'opposite direction to "the'rst iband` means and extending therefrom towards the second end of said sled, first con'- `n'ectn'e'means :connecting `the "first band -means to the first fendcf 'the-sled, second connecting means connecting the second band means to the second end of the sled, one of said connecting means having resilient `properties holding the band means tight and thereby holding said sled in alignment with and against the runner snr faces.

2. A unit for moving a tuning rod relative to an inductance coil, said unit comprising, a frame having opposite side walls dening a pair of spaced parallel runner surfaces, turnable drum means bearing in said side walls and extending therebetween transversely of said runner surfaces, a tuning rod support sled reciprocally slidable on said runner surfaces, said sled having a first end and a second end, first band means windably mounted in one direction on said drum means and extending therefrom towards said first end of said sled, second band means windably mounted on said drum means in an opposite direction to the rst band means and extending therefrom towards the second end of said sled, first connecting means connecting the first band means to the first end of the sled, second connecting means connecting the second band 6 means to the second end of the sled, one of said connecting means having resilient properties holding the band means tight and thereby holding said sled in alignment with and against the runner surfaces.

STANLEY A. HALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

